Cutting tools are used for removing material from a workpiece in order to manufacture therefrom a desired final element. There exists in common practice a great variety of operations for the removal of material, for each of which, a specific tool is designed. Cutting tools are usually in either the form of a single body or in the form of a tool holder with one or more replaceable cutting inserts mounted thereon. Examples of such operations are drilling, milling, turning, boring etc.
A majority of cutting tools or cutting inserts are formed with a cutting edge adapted to come in contact with the workpiece, within a cutting zone, so as to remove material therefrom during a cutting operation, the removed material being in the form of a chip.
Each cutting edge of a cutting tool or cutting insert is known to have a rake surface extending from the cutting edge in the direction away from the workpiece and a relief surface extending from the cutting edge transversely to the rake surface and generally facing in the direction of the workpiece, the cutting edge being defined at the intersection between its rake and relief surfaces.
The rake surface is adapted to come in contact with the removed chip, while the relief surface is generally designed so as not to come in contact with the workpiece during cutting operation.
It has been known to provide additional elements on the relief surface, for example, elements configured for deforming the workpiece prior to the cutting operation.
One such example is set forth by the applicant himself in WO09053803, which discloses a cutting element adapted for removing a chip from a surface of a workpiece has at least one cutting edge defined by an intersection line between a rake and a relief surface and is formed with one or more workpiece deforming protrusions. At least a portion of the protrusions is spaced from the cutting edge such this portion protrudes, along a plane perpendicular to the relief surface and passing through the cutting edge, in a direction transverse to the relief surface beyond the cutting edge. At least the projecting portion of at least one of the protrusions is constructed so as to deform the workpiece before its contact with the cutting edge.
Another example, also as set forth by the applicant himself is WO11001438, which discloses a cutting element for use in a cutting operation, comprising a cutting edge (CE) capable of cutting out material from a workpiece during the operation, to form therein a workpiece corner of angle alpha. There exists at least one view of the cutting edge in which a portion of the cutting edge is delimitable by a first (L1) and a second (L2) line oriented tangentially to the portion of the cutting edge portion at respective tangency points A and B. The lines form therebetween a cutting angle corresponding to the workpiece corner angle alpha and have a vertex 0. For a bisector of the cutting angle intersecting the portion of the cutting edge at the point C, the projection C of the point C of the portion of the cutting edge on a line OL passing through the vertex 0 perpendicularly to the plane of the one view is located between projections A1 and B′ of the respective points A and B of the portion of the cutting edge on the line OL.
It is also known to provide an auxiliary cutting element positioned on the relief surface and configured for removing additional material, on top of that removed by the main cutting edge of the cutting tool. One such example is set forth by the applicant himself in WO13175478A2 which discloses a method for designing a cutting edge of a cutting element configured for removing material from a workpiece to leave therein a desired end profile. The method comprises the steps of modeling a desired end profile of the workpiece, the profile having a longitudinal axis and being defined by a bottom surface, a side surface and an adjoining surface extending therebetween; defining a lead profile plane and an trail profile plane spaced therefrom, each of the planes being oriented perpendicular to the longitudinal axis; determining a profile contour defined by the intersection line between the end profile and the lead profile plane. The contour profile includes a bottom contour defined as the intersection line between the lead profile plane and the bottom surface, an adjoining contour defined as the intersection line between the lead profile plane and the adjoining surface, and a side contour defined as the intersection line between the lead profile plane and the side surface; designing a rake surface and a relief surface, the intersection line between which defines a cutting edge lying in the adjoining surface and spanning between the lead profile plane and the trail profile plane. The cutting edge is designed such that in any reference plane oriented perpendicular to the cutting edge, the intersection between each of the rake surface and the relief surface with the reference plane defines a respective rake line and relief line, the angle between the lines being equal to or smaller than a similar angle taken along each of a plurality of similar reference planes disposed between the reference plane and the lead profile plane
Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.